The race to succeed Paddy Ashdown as the next leader of the Liberal Democrat party accelerated yesterday as three new candidates joined the field in the wake of Simon Hughes' overnight declaration.

Nearly five months after Mr Ashdown signalled his retirement after 11 years rebuilding his shattered party, yesterday's entrants all came from those MPs most suspicious of their leader's intimacy with Tony Blair - and the unprecedented Lib-Lab cabinet committee it has spawned to promote cooperation on constitutional reform and foreign policy.

Amid earnest declarations of intent, none condemned Mr Ashdown's "project" in more than cautious terms, and all refrained from direct, personal attack.

Mr Ashdown's warning to stick to "constructive opposition" and the centre ground has been noted by them all.

Yesterday's most flamboyant campaign launch came from Jackie Ballard, MP for Taunton since 1997, who will fight on the slogan "Jackie B - Who Cares Wins".

The only woman in what is likely to be a six-horse race declared in Taunton, where Mr Ashdown's local inspiration first brought her into politics, then took a helicopter ride to London, Edinburgh and Manchester to sell her message as an advocate of economic as well as political devolution away from Westminster to the regions.

Malcolm Bruce, the party's treasury spokesman, also defied the pundits by joining the contest, which will be decided by a ballot of 90,000 Lib Dem members by August 8. So did David Rendel, winner of the Newbury byelection in 1994, and very much an outsider in this contest.

Mr Hughes, who won the Lib Dems an inner London seat in Bermondsey in 1992, beat his rivals from the starting blocks as soon as the Euro-election polls closed last night. The party's health spokesman proclaimed himself "the most senior" runner now that Menzies Campbell has dropped out, and claimed support from more than 200 local parties.

Next week will see the universally acclaimed Charles Kennedy, ex-party president and an MP since he was 23, declare on Tuesday. Don Foster, MP for Bath, will also declare on Tuesday. Paul Tyler, the party's chief whip, who considered entering the race, is now having second thoughts.

He will announce his decision on Monday. Either way, contestants will have a final four hour chance to withdraw with honour after formal nominations close on June 28. Mr Ashdown, who will not intervene in the contest, privately wants the field to shrink, but advocates of the single transferable vote version of proportional voting - the Lib Dems' favourite version - say it does not matter.

Ms Ballard spoke for most of them in saying that she wanted party voters to decide, not colleagues telling other MPs not to stand. She also set out her credentials as a radical by advocating a war on poverty - abroad as well as at home - to protect the environment and to advance civil rights. But she deplored left-right "pigeon holes."

On a more personal note Mr Rendel told supporters in Newbury town hall that he had "the energy and stamina to lead our party" of which he claimed a "deep understanding".

He wants the fate of the Lib-Lab cooperation to be decided by the party at large in what he calls a multi-option "preferendum" next summer after wide consultation.

Mr Bruce, MP for Gordon since 1983, said he had persuasive talents that could unite the party. As an English-born Scot who chose to be ed ucated in Scotland he called himself a "true Brit" who felt comfortable in both countries. But he too was cautious about condemning the Ashdown project.

Ms Ballard made a similar point. She said: "In May this year British politics changed forever - we are becoming a federal country. We now need a new leader of the party and a new style of leadership."